commit

tests/test_helios_laser.py

@@ -0,0 +1,160 @@
+"""HeliosLaser: replies that span more than one line.
+
+Regression: every status-register query answers with the value *and* a
+"Bit 15..0: ..." decode line.  The driver read one line per query and threw
+the rest away with reset_input_buffer(), which at 9600 baud cannot drop
+bytes that are still on the wire — so from the first LER read onward every
+reply was one line behind, and the panel showed a register as
+"Bit 15..0: 0000 0000 0000 0010" with the reads around it timing out.
+"""
+import pytest
+
+from hardware.helios_laser import HeliosLaser, PulseMode
+
+
+# What the controller actually sends back, per Section 6 of the operator's
+# manual and the LER/LCE/CCE tables in Section 8.
+REPLIES = {
+    "LDO": ["LDO = 1"],
+    "LDF": ["LDF = 20000 ns"],
+    "LDS": ["LDS = 1500 mA"],
+    "LDG": ["LDG = 14"],
+    "LRE": ["LRE = 0"],
+    "LTA": ["LTA = 25400 m°C"],
+    "LTT": ["LTT = 31200 m°C"],
+    "EOA": ["EOA = 40100 m°C"],
+    "CSR": ["CSR = 1234567"],
+    "HSR": ["HSR = 7654321"],
+    # The registers are the multi-line ones.
+    "LER": ["LER = 0", "Bit 15..0: 0000 0000 0000 0000"],
+    "LCE": ["LCE = 2", "Bit 15..0: 0000 0000 0000 0010"],
+    "CCE": ["CCE = 0", "Bit 15..0: 0000 0000 0000 0000"],
+}
+
+
+class FakePort:
+    """Serial stand-in that answers like the Helios controller.
+
+    ``reset_input_buffer`` is deliberately a no-op: the rest of a reply is
+    still in flight when the driver has read its first line, so a flush
+    cannot remove it.  The driver has to stay in step by reading what it
+    asked for, not by discarding what it happens to find.
+    """
+
+    def __init__(self, replies=None, timeout=1.0):
+        self.replies = REPLIES if replies is None else replies
+        self.timeout = timeout
+        self.is_open = True
+        self.written: list[str] = []
+        self._buf = bytearray()
+
+    # ── the bits of pyserial.Serial the driver uses ──────────────────────────
+
+    def write(self, data: bytes) -> int:
+        text = data.decode("ascii").strip()
+        self.written.append(text)
+        fields = text.split()
+        for line in self.replies.get(fields[0].upper() if fields else "", []):
+            self._buf += line.encode("utf-8") + b"\r\n"
+        return len(data)
+
+    @property
+    def in_waiting(self) -> int:
+        return len(self._buf)
+
+    def read(self, size: int = 1) -> bytes:
+        chunk = bytes(self._buf[:size])
+        del self._buf[:size]
+        return chunk
+
+    def read_until(self, expected: bytes = b"\n", size=None) -> bytes:
+        # No terminator in the buffer models the read timing out: pyserial
+        # returns whatever it has, which is b"" when nothing is pending.
+        cut = self._buf.find(expected)
+        cut = len(self._buf) if cut < 0 else cut + len(expected)
+        chunk = bytes(self._buf[:cut])
+        del self._buf[:cut]
+        return chunk
+
+    def reset_input_buffer(self):
+        """No-op — see the class docstring."""
+
+    def close(self):
+        self.is_open = False
+
+
+@pytest.fixture
+def laser():
+    """A connected driver on a fake port, with the idle wait taken out.
+
+    TRAILING_QUIET_S covers the ~30 ms a decode line spends on the wire at
+    9600 baud; the fake answers instantly, so waiting for it only slows the
+    suite down.  Zeroing it also keeps the tests honest: they pass because
+    the driver reads the whole reply, not because it waited long enough.
+    """
+    drv = HeliosLaser(timeout=1.0)
+    drv.serial = FakePort()
+    drv.is_connected = True
+    drv.TRAILING_QUIET_S = 0.0
+    return drv
+
+
+def test_status_registers_are_read_in_step(laser):
+    """The regression: each register gets its own value, not the previous
+    register's decode line."""
+    assert laser.get_status_registers() == (0, 2, 0)
+
+
+def test_reads_after_a_register_are_not_a_line_behind(laser):
+    """A whole status poll, in the order HeliosWorker._poll_once issues it."""
+    assert laser.get_status_registers() == (0, 2, 0)
+    assert laser.is_laser_enabled() is True
+    assert laser.get_current_ma() == 1500
+    assert laser.get_diode_temp_c() == pytest.approx(25.4)
+    assert laser.get_power_stage_temp_c() == pytest.approx(31.2)
+    assert laser.get_qswitch_temp_c() == pytest.approx(40.1)
+
+
+def test_decode_line_is_consumed_not_left_behind(laser):
+    laser.get_status_registers()
+    assert laser.serial.in_waiting == 0
+
+
+def test_unit_suffix_is_stripped(laser):
+    assert laser.get_frequency_hz() == 50000       # "LDF = 20000 ns"
+    assert laser.get_current_ma() == 1500          # "LDS = 1500 mA"
+
+
+def test_a_reply_from_an_earlier_command_is_skipped(laser):
+    """An answer already in the buffer when the query goes out belongs to
+    whoever asked for it, and must not be returned as this query's value."""
+    laser.serial._buf += b"LER = 8\r\nBit 15..0: 0000 0000 0000 1000\r\n"
+    assert laser.get_current_ma() == 1500
+
+
+def test_reply_without_a_mnemonic_is_taken_as_the_value(laser):
+    """The serial numbers come back as a bare string on some firmware."""
+    laser.serial.replies = {"CSR": ["A1B2C3D4"]}
+    assert laser.get_controller_serial() == "A1B2C3D4"
+
+
+def test_silent_device_reports_a_timeout(laser):
+    laser.serial.replies = {}
+    assert laser.get_current_ma() is None
+    assert laser._query("LTA") is None
+
+
+def test_set_commands_clear_their_acknowledgement(laser):
+    """A setter that leaves the controller's echo in the buffer desynchronises
+    the next query just as a decode line does."""
+    assert laser.set_laser_enable(True) is True
+    assert laser.serial.in_waiting == 0
+    assert laser.set_pulse_mode(PulseMode.CONTINUOUS_PULSING) is True
+    assert laser.get_current_ma() == 1500
+
+
+def test_raw_command_returns_every_line(laser):
+    """The diagnostics console is where a multi-line reply should be visible."""
+    assert laser.send_raw_command("LCE") == (
+        "LCE = 2\nBit 15..0: 0000 0000 0000 0010"
+    )